The purpose of the invention is to propose a method for bonding two electronic components by the insertion of hollow and open inserts into full elements, allowing an insertion under ambient atmosphere and without creating bubbles.
To this end, the invention is characterized in that, when an insert is inserted into a full convex element, at least one surface of the open end of the insert is left free (i.e., not in contact with the full element) so as to create an outlet passage for gases contained in the insert.
“Hollow insert” is here taken to mean a pattern protuberant from a surface, whereof the side walls form an internal open cavity, and whereof the thickness e of the walls is small relative to the dimensions of the cavity aperture, so as to define a small seat during the step of inserting the hollow insert into the full element, and therefore a small insertion force relative to the insertion of a full insert into a full element, thereby allowing the insert to be inserted into the full element under ambient atmosphere, with no thermo-compression or re-fusion step.
As a numerical example, the surface S′ defined by the walls of the hollow insert is smaller by at least half than the surface S of the cross-section of the hollow insert (S′<S/2). For example, in the case of a hollow tubular insert, the thickness e of the walls is less than a fifth of the external diameter D of the insert (e<D/5). Reference may be made to the application FR 08 51142 for an example of the determination of the thickness e of the walls of the hollow tubular insert relative to the insertion force of the hollow insert into the full element.
In a preferred way, the hollow insert is constituted by a thin film closed on itself with the cross-section thereof being small relative to the cross-section of the aperture.
In other words, a portion of the aperture of the insert is laterally offset from the full element with the result that this portion is never inserted therein. There is thus a passage for the gases to be expelled from between the insert and the full element during insertion. According to particular embodiments of the invention, the method includes one of more of the following features:                the open end of the insert is of greater length, along at least one predetermined axis, than the length of the full element along said at least one axis;        the open end of the insert has a plurality of branches partially arranged outside the full element during insertion;        the open end of the insert is circular;        the full elements form a pattern on one surface of one of the micro-components, in that the inserts form a pattern on one surface of the other of the micro-components, and the insertion is implemented by offsetting one pattern relative to the other so as to create an outlet passage for the gases in respect of each insert.        